Differential effects of acute cold and footshock on the sleep of rats

Differential effects of acute cold and footshock on the sleep of rats

Author Palma, B. D. Google Scholar
Suchecki, D. Google Scholar
Tufik, S. Google Scholar
Institution Universidade Federal de São Paulo (UNIFESP)
Abstract Several studies have shown that 1 h of immobilisation stress during the rat's active period results in rebound of paradoxical (PS) and slow wave sleep (SWS). Since the effects of stress on behaviour and physiological parameters vary according to the stimulus, the present study sought to examine the activation of the hypothalamic-pituitary-adrenal (HPA) axis and the sleep pattern of rats submitted to 1 h of footshock, immobilisation or cold, or 18 h of PS deprivation (PSD). Stress sessions began between 0900 and 0930 h. Immediately after the end of the stress session, or at the corresponding time for controls, animals were blood sampled for determination of ACTH and corticosterone (CORT) plasma levels. in Experiment 2, animals were implanted with electrodes for basal and post-stress polysomnographic recording (6 h long). the results showed that all stressors produced an activation of the HPA axis; however, footshock induced the largest ACTH levers, whereas cold resulted in the highest CORT levels. in regard to the sleep data, immobilisation and PSD led to a rebound of SWS (+16.87% and +9.37%, respectively) and PS (+42.45% and +55.25%, respectively). Immobilisation, however, induced an increased number of PS episodes, whereas PSD resulted in longer PS episodes. Cold stress produced an exclusive rebound of SWS (+ 14.23%) and footshock promoted sustained alertness during the animal's resting period ( + 47.18%). These results indicate that different stimuli altered the sleep pattern in a distinct manner; and these alterations might be related to the state of the HPA axis activation. (C) 2000 Published by Elsevier Science B.V. All rights reserved.
Keywords acute stress
sleep architecture
HPA axis
polysomnography
rat
Language English
Date 2000-04-07
Published in Brain Research. Amsterdam: Elsevier B.V., v. 861, n. 1, p. 97-104, 2000.
ISSN 0006-8993 (Sherpa/Romeo, impact factor)
Publisher Elsevier B.V.
Extent 97-104
Origin http://dx.doi.org/10.1016/S0006-8993(00)02024-2
Access rights Closed access
Type Article
Web of Science ID WOS:000086349900011
URI http://repositorio.unifesp.br/handle/11600/26293

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